The food industry has invested a significant research and development effort to identify food ingredient products that can exhibit a sensory perception of fattiness in foods without the high calorie content of common oil and fat-containing ingredients. Generally, it has been found that the fatty sensation detected in the mouth is entirely a phenomenon of rheology. There are no sensors in the mouth for fats as there are for sweetness and saltiness. Instead, the sensation of fattiness is a complex sensation involving interrelated viscosity and flowability properties of a food product.
The scientific literature contains multiple references to the organoleptic sensation produced in the mouth By particular components of foods. For example, certain protein and carbohydrate compositions are proposed as fat replacements in U.S. Pat. No. 4,911,946 and references identified therein. Carbohydrates and proteins have less than one-half of the calories of available metabolic energy than carbohydrates on a per gram basis. Two significant proteins, namely whey protein and egg white protein, in the form of microspheres of about 1-10 microns have been made by at least two companies for use as fat mimics. U.S. Pat. No. 4,911,946 also suggests that small, substantially spherical carbohydrate-based particles, including small whole starch granules in the 0.1-3 micron diameter range, are acceptable fat mimics.
This invention relates to an improved granular starch-derived composition for use as a fat mimic. It is based on the discovery that small granule starches, generally those having an average granule size of 5 microns or less, more particularly those averaging 3 microns or less in diameter undergo an unusual, heretofore unrecognized, surface modification, upon partial hydrolysis with amylase at temperatures below the starch gelatinization temperature. Generally, it is reported in the patent and non-patent literature that enzymatic hydrolysis of granular starch at temperatures below the starch gelatinization temperature provides porositized or cavitated granule surfaces readily discernible by microscopic examination. In many instances the starch granules are reduced to a sponge-like structure deriving from uneven hydrolysis. In theory the starch polymers in the regions of lesser crystallinity undergo enzyme mediated hydrolysis at higher rates than those areas of greater crystallinity on the starch surface.
It has been found that granular starches having an average granule diameter of about 5 microns or less, for example amaranth, quinoa, and taro are not porositized or cavitated upon treatment with amylase at temperatures below the respective granular starch gelatinization temperatures. Instead, enzymatic hydrolysis of such granular starches under nongelatinizing conditions produce partially hydrolyzed granules which have a surface appearing very diffuse or amorphous and substantially non-porous under microscopic examination, and which exhibit crystallinity characteristic of the corresponding native starch granules, as determined by x-ray or microscopic analysis with polarized light.
The partially hydrolyzed small granule starch compositions in accordance with this invention exhibit improved fat substitute functionality. When used as a substitute for at least a portion of the fat content of processed foods, the hydrolyzed small granule starch imparts the sensory perception of fattiness with less calorie content and without compromise of other organoleptic qualities of the modified food product. The enzyme hydrolyzed small granule starches in accordance with the invention are optionally treated with a surface modifying agent to complement the functional qualities of the starch composition.
Thus, in accordance with the present invention there is provided a partially hydrolyzed small granule starch which exhibits exceptional fat mimic characteristics in processed foods.
Another embodiment of the present invention provides a method of preparing an improved granular starch based fat substitute for processed foods.
Still another embodiment of the present invention is a process for modifying the recipe of a processed food to reduce the calorie content without compromising its organoleptic qualities.